A set of interconnected planetary diagrams covering the Ancient Khmer Empire and brought to light by temples built on key locations reveals capacities, in the fields of astronomy, land-surveying and cartography, which exceed by far the know-how and accuracy previously attributed to Middle-Age scholars.

As a matter of fact, the locations provided by the inscription are fully correct if we suppose the degree zero of the first house-sign was Spica instead of zeta Piscium. It is worth remembering the Indian (and the Khmer) used to measure the « ayanamsa » ie the difference of ecliptic longitude between the vernal equinox and the star used as degree zero of their zodiac. These stars were either Spica or zeta Piscium.

By using Spica (the house numbers become those written in green colour in figure):

The basis of this research is the stanza XLIV of the inscription carved on the stele discovered in the fourth enclosure’s gopura of the Banteay Srei temple. We are able to demonstrate the stanza provides the houses-signs where the planets, the Sun and the Moon were located on 22 april 967 CE (Julian calendar) at midnight (24 h) although the indicated locations are not, at first sight, compatible with the year when the temple was consecrated. The « Siddhantic » software (HIC), created by Lars Gislén ( http://home.thep.lu.se/~larsg/Site/Welcome.html ), calculates the following locations (figure here below) :

-Sun, Mercury and Saturn (red numbers 1, 4 & 7) were located in the house-sign 0 (numbers written in black colour in the figure). With zeta Piscium used as degree zero (usual convention), the three objects were crossing, roughly, the Aries constellation.

The Indians used apsides lines which were practically fixed with respect to the star used as degree zero (usually zeta Piscium) but the apsides lines were, of course, (due to precession) shifting with respect to the vernal equinox . As our current web page diagrams were drawn from ecliptic longitudes calculated from the vernal equinox (the only method used nowadays), we should have included the precession of the apsides from 499 CE (epoch of reference of Indian calculations) to 967 CE. Unfortunately, we did not include the precessional shift in the current web pages. The current diagrams will need to be corrected (butthe differences are not great).